Internal combustion engine



Aug. 16, 1932. M. TIBBETTS 1,871,480

INTERNAL COMBUSTION ENGINE Original Filed Jam 7, 1929 Patented Aug. 16, 1932 UNITED STATES PATENT orrica MILTON .TIIBBETTS, OF DETROIT, MIGHIGAN,.ASSIGNO I TOPACIKARD MOTOBCAR COM- PANELOF DETROIT, MICHIGAN, A CORPOB TION OF MICHIGAN INTERNAL COMBUSTION ENGINE I Applicatlon filed January 7, 1929, Serial No. 330,889. Benewed September 23, 1981.

of the first bearing 13, the crank shaft is re- This invention relates to internal combustion engines and particularly to means .for controlling torsional vibration in the shafts of such en ines.-

3} It has or one of its objects to provide a reliable'and'effective vibration damper for shafts subjected to such torsional vibration.

Another object of the invention is to provide a vibration damper which shallbe free from unbalance caused by non-uniform opggation of the speed responsive weight memr. Another object of the invention is to pro- ,vide a vibration damper in which sticking and bindin shall be obviated and in which there shall no rusting or corroding of the parts "and no improper adherence therebetween. s

A further object of the inventim is to provide a vibration damper having but few arts of simple construction, which shall be 1nex pensive to build and easy to operate and maintain.

Other objects of the invention will appear '25 from the following description taken in connection with the drawin which forms a part of this specification, an in ,which the single figure is a. view partially in side elevation and partially in vertical longitudinal section, through a portion of an internal combustion engine having a vibration damper'constructin cranks 16, which crank shaft is adapted 0. 5

e driven by-connecting rods 17 from pistons located in the engine cylinders (not shown). The lower part of the crank case is closed by an oil pan 18, removably'secured thereto in any suitable manner, thus providing a sump for the lubricating oil of the engine. This oil is circulated to the various engine bearings in any convenient wa as by means of pipes such as 19, the over ow returnin to the sump. Ma i e forward end of the engine, in front duced in diameter as at 21, and a sprocket gear 22 is mounted thereon and connected by means of a key 23 to rotate with the shaft.

This sprocket is adapted to drive a flexible chain 24 by means of which the cam shaft, thegenerator shaft, and other auxiliaries to the englne proper (not shown) maybe driven.

The damping means of the invention is 'ilvlustrated as mounted at the end of the engine crank shaft upon a. suitable bearing part thereon, and it comprises'a hub member 26, keyed as at 27 to a reduced portion 28 of the shaft, on which a pair of spaced inertia members 29 are rotatably mounted. The

hub member 26 is provided with an integral flange 32, and is secured against axial movement on the crank shaft by a retaining member adapted to clamp it against the hub of the sprocket 22. The retaining member ma be a pulley 33, also keyed to the crank sha t and adapted to drive the en 'ne fan (not shown) through a suitable elt 34. The member 33 may be retained on the shaft by a bolt member 36, threaded into the end of the shaft, and having a pulley engaging head portion 37, which may also constitute the usual startin .jaw for cooperation with a suitable cran for. manually rotating the crank shaft in starting the engine. The flange 32 and the pulley 33 thus provide spaced braking members between which the inertia members are mounted, and which are preferably provided withsuitable friction material 38 for bra-kingengagement with the adjacent side faces of the inertia members 29. The friction thus provided causes the damping action. The inertia members 29 are constrained to rotate together in any convenient manner, as by a dowel 39, and are also provided with oppositely disposed aligned recesses 41 in which suitable compression springs 42'are disposed. These springs urge the inertia members axially apart and into initial frictional engagement with-their respective braking members.

suflicient friction to secure initial damping at low engine speeds is provided. To provide for increased damping at the higher speeds, the damper is provided with In this way speed responsive means operable to increase the axial pressure, urging the inertia members apart to increase the braking pressure on the friction facings 38, and accordingly the damping friction. To this end each of the inertia members 29 is provided with a circular groove 43 in its radial face, having an tends to axially expand or separate the in-- ertia members 29, to increase the damping friction as previously explained.

In devices of this character heretofore constructed, the inertia members are usuall formed of iron or steel, which material is su ficiently heavy and has the requisite mechanical 'strength.- It has been found, however, flm't considerable trouble is caused in the operation'of such dampers by adhesion between those inertia members and the rubber ring 496.

Such adhesion tends to prevent the operation of the damper, which then operates simply as a secondary fly wheel, the initial friction being insufficient to ade uately damp the shaft vibration at the big er speeds. Such adhesion may be caused by a rusting together of the parts, or by sticking of the ring 46 through partial vulcanization of the rubher from the heat of friction. When such adhesion occurs at a part only of the contacting surfaces, the rin 46 is unequall expanded or distorted by t e centrifugal o'rce, causing an unbalance of the damper, which results in a rough and noisy engine. Such a damper, if continued in operation may cause serious damage to the crank shaft, bearings and associated parts of the engine.

To obviate these difficulties, this invention rovides means to prevent such adherence etween the ring 46 and the inertia members. For this purpose a shield member or liner 47 is (provided between each of the grooves 43 an the cooperating rin 46, these liners being formed of a non-a erent and noncorrodible material, such as brass or bronze, which will not rust and to which the heated rubber will not stick. The liners 47 are conveniently formed of thin stampings of sheet brass or other suitable metal, but it is to be understood that the invention is not limited to brass or to any other metal,-nor to material in the form of stampings, but that any suitable non-adherent and non-corrosive lining material may be used. These liners are formed to correspond'to the shape of the grooves 43, and are placed th'erein before assembl of the damper, being thereafter retaine in position by the pressure of the rubber ring 46 with which they are in contact.

The operation of the device will be readily understood without further ex lanation, from the above description, and it will be apparent that this invention provides a simple and inexpensive device whereb difliculties caused by the adherence 0 such dam rs are completely obviated.

W ile a specific embodiment of the invention has been herein described, which is deemed to be new and advantageous and may be specifically claimed, it is not to be un erstood that the invention is limited to the exact details of the construction, as it will be apparent that changes may be made therein without departing from the spirit or scope of the invention.

Having thus described the invention, what is claimed and desired to be secured by'Letters Patent is:

1. A vibration damper .for shafts com ris-' ing inertia members rotatably mounte on the shaft, friction means between the inertia members and the shaft, expansible weight means carried by the inertia members and operable in response to centrifugal force to urge said inertia members into eng ement with the friction means, and a liner 0 material non-adherent to the weight means carried by the inertia members andinterposed between the inertia members and said weigh means.

2. A vibration damper for shafts com rising friction members secured to the s aft, rotatable inertia members axially separable to engage the friction members, an annular wedge member radially expansible in response to centrifugal force to separate said inertia members and a solid anti-friction liner carried by the inertia members and interposed between the wedge member and each inertia member.

3. A vibration damper for shafts comprisin friction members secured to the shaft,

rotata le inertia members axially separable to engage the friction members having inclined faces, an annular resilient wedge member having a mounting ofheavy material between the inclined faces adapted to urge the inertia members apart upon expansion in responseto centrifugal force, and a rustless liner carriedby the inertia members and interposed between each inertia member and the wedge member.

4. A vibration damper having inertia members, a speed responsive weight device cooperating therewith, and a shield member non-adherent to the weight device carried by the inertia members and interposed between the inertia members and'the weight device.

5. In a vibration damper having inertia members and a speed onsive weight (le vice cooperating therewith, said members and said weight device having engaging portions relatively movable in response to speedchanges, a liner carried by said members and interposed between the said relatively movable portions of the members and the weight device to prevent adhesion therebetween.

6. A vibration damper for shafts comprising inertia members each having a groove, said grooves cooperating to form a channel, friction means on said shaft, speed responsive means between said inertia members in said channel adapted to engage said members with said friction means, and a liner in each oove to prevent adhesiombetween the inertia members and said speed responsive means. 7

7. The combination with a vibration damper for shafts having friction means on said shaft and inertia members rotatably mounted on the shaft and axially separable to engage said friction means, of resilient weight means between the inertia members radially expansible in response to centrifugal force to increase the axial pressure of the inertia members on the friction means, and liners of soft metalnon-adherent to said weight means carried by said inertia members and interposed between the inertia members and said weight means.

8. A vibration damper for shafts comprising friction members secured to the shaft, rotatable inertia members axially separable to engage the friction members, an annular wedge member radially expansible in re spouse to centrifugal force to separate said inertia members, and strips of material nonadherent to said wedge member carried by the inertia members and interposed between each inertia member and the wedge member.

9. A vibration damper for shaftscomprising friction members secured to the shaft, rotatable inertia members axially separable to engage the friction members, an annular wedge member radially expansible in reand interposed between the expansible weight means and the said member.

11. A vibration damper for a shaft oomrising-an inertia member and a thrust memr, said members bein mounted for rotation with res ect to sai shaft, an abutment carried by sald shaft for limiting axial movement of said inertia member and having frictional connection therewith, means radially and axially expansible in response to centrifugal force interposed between said members to urge said inertia member axially, and an anti-friction liner carried by and interposed between said means and said inertia member. a

In testimony whereof I ,aflix my signature.

MILTON TIBBETTS.

sponse to centrifugal force to separate said inertia members, and annular liners of antifriction material carried by said inertia members and interposed between the wedge member and each inertia member.

10. A vibration damper for a shaft comprising aninertia member mounted for rotation with respect to the shaft, a member mounted for rotation with the shaft and having a frictional connection with saidinertia member, one of said members being movable axially of the shaft with respect to the other to vary the friction, expansible weight means engaging one of said members and operable in response to centrifugal force to urge the member engaged thereby axially of the shaft, and a hner of material non-adherent to the weight means carried by the inertia member 

